System and method for providing poisition information of mobile terminal using cellular broadcasting technology

ABSTRACT

There are provided a system and a method for providing position information of a mobile terminal using cellular broadcasting technology. The ephemeris and almanac information of the GPS satellite required for calculating the position of the mobile terminal are broadcasted by the CBS through the BTS to which the mobile terminal is pertinent, so that the call processing procedure between the mobile terminal and the PDE which is usually carried out to obtain the position information of the GPS satellite may be omitted. In the case that the position of the mobile terminal is changed in real time by a vehicle or the like, it can provide very precisely the position information of the mobile terminal since the time consumed for the mobile terminal to define the traffic channel for obtaining the position information of the GPS satellite is reduced. In addition, in the system of the present invention, since the call processing procedure is simplified, a load applied to the PDE is reduced, so that it can suppress the additional installation of the PDE which is an expensive device relative to other components.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a system and a method for providingposition information of a mobile terminal using cellular broadcastingtechnology, and more particularly, to a system and a method forreceiving position information from a satellite of GPS, broadcasting theinformation in a unit of cell such that the mobile terminal in apertinent cell may calculate position information thereof and providethe information to the system.

2. Description of the Related Art

Due to development of mobile communication technology, it has beenproposed a mobile communication network having a function of tracing aposition of a mobile terminal using position information transmittedfrom a satellite of Global Positioning System (GPS). The satellite ofGPS transmits almanac information indicative of its own position andephemeris information indicative of more precise position of thesatellite of pertinent GPS. An earth station for satellite communicationreceives the almanac information and the ephemeris information and sendsthem to a mobile communication network. The almanac information and theephemeris information are referred to as position information of thesatellite of GPS. The mobile communication network calculates theposition information of the mobile terminal using the positioninformation of the satellite of GPS.

FIG. 1 is a schematic view illustrating a construction of a conventionalsystem for providing position information of a mobile terminal.

Referring to FIG. 1, a conventional mobile communication networkgenerally includes a base station transceiver subsystem (BTS) 21, a basestation controller (BSC) 22, and a PCS central exchange (PCX) 23. Amobile positioning center (MPC) 24 and a position determination entity(PDE) 25 which integrally manage the position information of the mobileterminal support a function of providing the position information of amobile terminal 10 in the mobile communication network. An applicationservice provider (ASP) 26 is connected to the mobile communicationnetwork to provide supplementary services.

Each of the BTSs 21 is allocated to one cell of a desired dimension, anda predetermined number of BTSs are connected to the BSC 22. Apredetermined number of BSCs 22 are connected to the PCX 23 to provide acommunication function of the mobile terminal. On the other hand, thePCX 23 are connected to the MPC 24, the PDE 25 and the ASP 26 in turn.The PDE 25 is connected to an earth station 27 for satellitecommunication to receive the position information of the satellite 30 ofGPS.

The conventional system configured as described above will now bedescribed with reference to FIG. 2 depicting a call processingprocedure.

The mobile terminal 10 is connected to the mobile communication networkvia TCP/IP or a data burst message (DBM) to define a traffic channel,and notifies the PDE 25 of the information of the BTS 21, to which thecurrent mobile terminal is pertinent, via the mobile communicationnetwork, as well as pilot phase measurements. At the same time, themobile terminal 10 requests the PDE 25 for location response, almanacinformation and ephemeris information (step S1). The location responseis approximately current position data (latitude and longitude) of themobile terminal 10 which is calculated by the PED 25 on the basis of theBTS 21. The BTS 25 determines a satellite of GPS to be effectively usedat the position of the current mobile terminal 10 based on theinformation of the mobile terminal and the pilot phase measurestransmitted via the mobile communication network and the MPC 24,receives the determined position information (almanac and ephemeris) ofthe satellite of GPS from the earth station 27 for the satellitecommunication 27, and transmits the position information and thelocation response to the pertinent mobile terminal 10 via the MPC 24 andthe mobile communication network (step S2). The mobile terminal 10conducts a search for the pertinent satellite of GPS using the locationresponse transmitted from the PDE 25 and the position information of thesatellite of GPS, so as to measure a phase difference between theterminal and the satellite of GPS and then calculate its own location.The mobile terminal 10 obtains its own position information, and sets anoperation end flag as “1”. Status information of the mobile terminal istransmitted to the PDE 25 via the mobile communication network and theMPC 24 (step S3).

The conventional system configured as described above has a disadvantageof prolonging a call processing time due to the complicated callprocessing procedure. Specifically, when the position tracing functionis performed, the mobile terminal executes application service to definethe traffic channel with a position determination device. Also, themobile terminal provides the information of the terminal (information ofthe earth station to which the mobile terminal is pertinent) and thepilot phase measures, and simultaneously, requests the PDE for thelocation response, the ephemeris information and the almanacinformation. A considerable time is consumed so that the mobile terminaldefines the traffic channel with the PDE. In the case where the mobileterminal is moving at that point, an error is caused in the positionmeasurement of the mobile terminal. The PDE should maintain a sessionwith the mobile terminal to provide the position tracing function. Assuch, if the call processing procedure between the mobile terminal andthe PDE is complicated, an excessive load is applied to the PDE, so thatan expensive server is additionally required.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to a system and a methodfor providing position information of a mobile terminal using cellularbroadcasting technology that substantially obviates one or more problemsdue to limitations and disadvantages of the prior art.

It is an object of the present invention to provide a system and amethod for broadcasting information in the unit of cell such that amobile terminal in a pertinent cell may calculate position informationthereof and provide the information to the system, thereby simplifying acall processing procedure between the mobile terminal and a positiondetermination entity and providing real-time position information of themobile terminal.

To achieve these objects and other advantages and in accordance with thepurpose of the invention, as embodied and broadly described herein,there is provided a system for providing position information of amobile terminal using cellular broadcasting technology, and the systemincludes a mobile communication network including a plurality of basestation transceiver subsystems each installed in one cell in a desiredservice area divided in a unit of cell and transmitting a signal fordefining call setting with the mobile terminal in a pertinent cell, abase station controller installed in the unit of at least one basestation transceiver subsystem for controlling a function of thepertinent base station transceiver subsystem, and a PCS central exchangeinstalled in the unit of at least one base station controller, anddefining and maintaining the traffic channel; a cellular broadcastingsystem for broadcasting position information of a GPS satellite via themobile communication network in the unit of cell, the broadcasting beingserviced by each base station transceiver subsystem of the mobilecommunication network; a mobile positioning center for transmitting asignal required to trace the position of the mobile terminal andtransmitting the position information of the GPS satellite to thecellular broadcasting system; and a position determination entity forclassifying the position information consisting of ephemeris and almanacinformation received from the GPS satellite in the unit of cell servicedby each base station transceiver subsystem of the mobile communicationnetwork to provide the mobile positioning center with the positioninformation.

Additional advantages, objects, and features of the invention will beset forth in part in the description which follows and in part willbecome apparent to those having ordinary skill in the art uponexamination of the following or may be learned from practice of theinvention. The objectives and other advantages of the invention may berealized and attained by the structure particularly pointed out in thewritten description and claims hereof as well as the appended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this application, illustrate embodiment(s) of the invention andtogether with the description serve to explain the principle of theinvention. In the drawings:

FIG. 1 is a schematic view illustrating a construction of a conventionalsystem for providing position information of a mobile terminal;

FIG. 2 shows a call processing procedure applied to the system of FIG.1;

FIG. 3 is a schematic view illustrating a construction of a system forproviding position information of a mobile terminal using cellularbroadcasting technology according to one preferred embodiment of thepresent invention; and

FIG. 4 shows a call processing procedure applied to the system of FIG.3.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Reference will now be made in detail to the preferred embodiment of thepresent invention, an example of which is illustrated in theaccompanying drawings.

FIG. 3 is a schematic view illustrating a construction of a system forproviding position information of a mobile terminal using cellularbroadcasting technology according to one preferred embodiment of thepresent invention, and FIG. 4 shows a call processing procedure appliedto the system of FIG. 3.

As shown in FIG. 3, the system according to one preferred embodiment ofthe present invention includes a mobile communication network fordefining a traffic channel with a mobile terminal, a cellularbroadcasting system (CBS) 44 for broadcasting position information of asatellite of GPS via the mobile communication network in the unit ofcell, the broadcasting being serviced by each base station of the mobilecommunication network, a mobile positioning center (MPC) 45 fortransmitting a signal required to trace the position of the mobileterminal and also transmitting the position information of the GPSsatellite to the cellular broadcasting system, and a positiondetermination entity (PDE) 46 for classifying the position informationconsisting of ephemeris and almanac information of the GPS satellite inthe unit of cell serviced by each base station of the mobilecommunication network to provide the MPC with the position information.

The mobile communication network includes a plurality of base stationtransceiver subsystems (BTSs) 41 each installed in one cell in a desiredservice area divided in the unit of cell and transmitting a signal fordefining call setting with the mobile terminal in the pertinent cell, abase station controller (BSC) 42 installed in the unit of at least oneBTS for controlling a function of the pertinent BTS, and a PCS centralexchange (PCX) 43 installed in the unit of at least one BSC 42 anddefining and maintaining the traffic channel.

The PDE 46 is connected to an earth station 48 for satellitecommunication to receive the position information consisting ofephemeris and almanac information of each GPS satellite from a pluralityof GPS satellites 30. Also, the PDE 46 is connected to an applicationservice provider (ASP) 47 to provide the mobile terminal 10 withsupplementary application services related to the position trace. Themobile terminal 10 sets the traffic channel in a usable state to receivethe position information (ephemeris and almanac) of the GPS satellitevia a CBS message.

The PDE 46 receives the position information containing ephemeris andalmanac of the GPS satellite 30 which is received by the earth station48 for satellite communication. The transmitted ephemeris and almanacinformation of the GPS satellite are classified in the unit of cell ofthe mobile communication network. The GPS satellites effectivelyavailable in each cell of the mobile communication network are differentevery cell. Therefore, the position information of the GPS satelliterequired in each cell is different to each other. In the systemaccording to the embodiment of the present invention, the informationrelated to the GPS satellite usable in each cell is predetermined in thePDE 46. The PDE 46 classifies the position information of the GPSsatellite in the unit of cell by using the predetermined information.The position information of the GPS satellite transmitted from the PDE46 is sent to the CBS 44 via the MPC 45. The CBS 44 broadcasts theposition information of the GPS satellite transmitted in the unit ofcell of the mobile communication network at a desired period of time,for example a period of 30 minutes to 2 hours. Each BTS of the mobilecommunication network transmits the broadcasted position information ofthe GPS satellite to each mobile terminal 30 placed in the cell areaserviced by the current BTS. Accordingly, it is possible for the mobileterminal 10 to receive the position information of the GPS satellite tobe effectively utilized in the location of interest from the BTS 41servicing the cell where the terminal is placed. Then, the mobileterminal 10 conducts a search for the GPS satellite using the receivedthe position information of the GPS satellite, and calculates its ownlocation using pseudorange data between the GPS satellite and the mobileterminal.

On the other hand, according to the system of the present invention, theCBS 44 broadcasts the position information of the GPS satellite to amobile terminal 10 in a pertinent cell in the unit of a desired timethrough each BTS 41 of the mobile communication network. If a power ofthe mobile terminal 10 is switched from OFF to ON, the respective mobileterminals 10 does not receive the position information of the GPSsatellite through the CBS 44 until the broadcasting period is achieved.Accordingly, at the initial power ON of the mobile terminal 10, themobile terminal 10 should request the position information of the GPSsatellite separately. Thus, at the initial power ON of the mobileterminal 10, the mobile terminal 10 requests the position information ofthe GPS satellite, according to a process shown in FIG. 2, andcalculates its own position using the response to the request.

With above description of the system and the method of the presentinvention, the ephemeris and almanac information of the GPS satelliterequired for calculating the position of the mobile terminal arebroadcasted by the CBS through the BTS to which the mobile terminal ispertinent, so that the call processing procedure between the mobileterminal and the PDE, which is usually carried out to obtain theposition information of the GPS satellite, may be omitted. The systemand the method of the present invention can save about 10 seconds neededfor the mobile terminal to define the traffic channel in order to obtainthe position information of the GPS satellite. The call processingprocedure is simplified in relation to the conventional system, therebyadditionally reducing about 1 or 2 seconds. Accordingly, the system andthe method of the present invention can save about 12 seconds inrelation to the conventional system. In the case that the position ofthe mobile terminal is changed in real time by a vehicle or the like, itcan provide very precisely the position information of the mobileterminal.

In addition, in the system of the present invention, since the callprocessing procedure is simplified, a load applied to the PDE isreduced, so that it can suppress the additional installation of the PDEwhich is an expensive device relative to other components.

The foregoing embodiment is merely exemplary and is not to be construedas limiting the present invention. The present teachings can be readilyapplied to other types of apparatuses. The description of the presentinvention is intended to be illustrative, and not to limit the scope ofthe claims. Many alternatives, modifications, and variations will beapparent to those skilled in the art.

1. A system for providing position information of a mobile terminalusing cellular broadcasting technology, the system comprising: a mobilecommunication network including a plurality of base station transceiversubsystems each installed in one cell in a desired service area dividedin a unit of cell and transmitting a signal for defining call settingwith the mobile terminal in a pertinent cell, a base station controllerinstalled in the unit of at least one base station transceiver subsystemfor controlling a function of the pertinent base station transceiversubsystem, and a PCS central exchange installed in the unit of at leastone base station controller, and defining and maintaining the trafficchannel; a cellular broadcasting system for broadcasting positioninformation of a GPS satellite via the mobile communication network inthe unit of cell, the broadcasting being serviced by each base stationtransceiver subsystem of the mobile communication network; a mobilepositioning center for transmitting a signal required to trace theposition of the mobile terminal and transmitting the positioninformation of the GPS satellite to the cellular broadcasting system;and a position determination entity for classifying the positioninformation consisting of ephemeris and almanac information receivedfrom the GPS satellite in the unit of cell serviced by each base stationtransceiver subsystem of the mobile communication network to provide themobile positioning center with the position information.
 2. The systemas claimed in claim 1, wherein the position determination entity isconnected to an earth station for satellite communication to receive theposition information consisting of the ephemeris and almanac informationof each GPS satellite from the earth station.
 3. The system as claimedin claim 1, wherein the position determination entity is connected to anapplication service provider to provide the mobile terminal withsupplementary application services related to the position trace.
 4. Thesystem as claimed in claim 1, wherein the information related to the GPSsatellite usable in each cell of the mobile communication network ispredetermined in the position determination entity, and the positiondetermination entity classifies the position information of the GPSsatellite in the unit of cell by using the predetermined information. 5.The system as claimed in claim 1, wherein the mobile terminal receivesthe position information of the GPS satellite to be effectively utilizedin the location of interest from the base station transceiver subsystemservicing the cell in which the terminal is placed, and the mobileterminal conducts a search for the GPS satellite using the receivedposition information of the GPS satellite, and calculates its ownlocation using pseudorange data between the searched GPS satellite andthe mobile terminal.